Light emitting diode package structure and manufacturing method thereof

ABSTRACT

A manufacturing method of a light emitting diode (LED) package structure includes the following steps. A carrier is provided. A redistribution layer is formed on the carrier. A plurality of active devices are formed on the carrier. A plurality of LEDs are transferred on the redistribution layer. The LEDs and the active devices are respectively electrically connected to the redistribution layer. The active devices are adapted to drive the LEDs, respectively. A molding compound is formed on the redistribution layer to encapsulate the LEDs. The carrier is removed to expose a bottom surface of the redistribution layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan applicationserial no. 109113363, filed on Apr. 21, 2020. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND 1. Technical Field

The disclosure relates to a package structure and a manufacturing methodthereof, and more particularly, to a light emitting diode (LED) packagestructure and a manufacturing method thereof.

2. Description of Related Art

At present, passive-matrix (PM) driving printed circuit board (PCB)backplanes are widely employed in large-scale micro light emitting diode(LED) displays. However, such PM driving PCB backplanes require a largenumber of driving chips, and therefore are expensive. Comparatively, inthin film transistor (TFT) backplanes according to the active matrix(AM) driving method, driving chips are integrated on the glasssubstrates. Although such AM driving TFT backplane costs less in price,it is difficult to manufacture a large-scale display driven by the AMdriving TFT backplane since electronic devices cannot be soldered on theback surface of the glass substrate.

SUMMARY

The disclosure provides a light emitting diode (LED) package structure,which addresses the issue that electronic devices cannot be soldered onthe back surface of a glass substrate. In addition, the LED packagestructure renders a lower cost.

The disclosure further provides a manufacturing method of the LEDpackage structure. According to the manufacturing method, themanufacturing cost is low.

According to an embodiment of the disclosure, a manufacturing method ofa light emitting diode (LED) package structure includes the followingsteps. A carrier is provided. A redistribution layer is formed on thecarrier. A plurality of active devices are formed on the carrier. Aplurality of LEDs are transferred onto the redistribution layer. TheLEDs and the active devices are respectively electrically connected tothe redistribution layer. The active devices are adapted to drive theLEDs, respectively. A molding compound is formed on the redistributionlayer to encapsulate the LEDs. The carrier is removed to expose a bottomsurface of the redistribution layer.

According to an embodiment of the disclosure, the redistribution layeris formed on the carrier before the plurality of active devices areformed on the carrier.

According to an embodiment of the disclosure, the carrier includes arelease film, and the redistribution layer is located on the releasefilm. When the carrier is removed, the release film is peeled off toseparate the redistribution layer and the carrier.

According to an embodiment of the disclosure, the active devices and theLEDs are located on a side of the redistribution layer relatively awayfrom the carrier.

According to an embodiment of the disclosure, each of the LEDs includesan active surface and a back surface opposite to each other, and theactive surface is located between the back surface and theredistribution layer.

According to an embodiment of the disclosure, the manufacturing methodfurther includes the following steps. Before the LEDs are transferredonto the redistribution layer, a dielectric layer is formed on theredistribution layer. The dielectric layer covers the active devices,and includes a plurality of openings to expose a portion of theredistribution layer. A surface treatment layer is formed in theopenings, and directly contacts the redistribution layer.

According to an embodiment of the disclosure, each of the LEDs includesan active surface and a back surface opposite to each other, and theback surface is located between the active surface and theredistribution layer.

According to an embodiment of the disclosure, the manufacturing methodfurther includes the following steps. Before the molding compound isformed on the redistribution layer, a dielectric layer is formed on theredistribution layer. The dielectric layer covers the active devices andthe LEDs. The active surface of each of the LEDs is aligned to a surfaceof the dielectric layer. The dielectric layer includes a plurality ofopenings to expose a portion of the redistribution layer. A plurality ofcircuits are formed in the openings, and extend to the surface of thedielectric layer to connect the active surface of each of the LEDs.

According to an embodiment of the disclosure, the active devices areformed on the carrier before the redistribution layer is formed on thecarrier.

According to an embodiment of the disclosure, the carrier includes arelease film, and the active devices and the redistribution layer arelocated on the release film.

According to an embodiment of the disclosure, when the carrier isremoved, the release film is peeled off to expose the bottom surface ofthe redistribution layer and surfaces of the active devices.

According to an embodiment of the disclosure, each of the LEDs includesan active surface and a back surface opposite to each other, and theactive surface is located between the back surface and theredistribution layer.

According to an embodiment of the disclosure, before the LEDs aretransferred onto the redistribution layer, a dielectric layer is formedon the redistribution layer. The dielectric layer includes a pluralityof openings to expose a portion of the redistribution layer. A surfacetreatment layer is formed in the openings, and directly contacts theredistribution layer.

According to an embodiment of the disclosure, each of the LEDs includesan active surface and a back surface opposite to each other, and theback surface is located between the active surface and theredistribution layer.

According to an embodiment of the disclosure, the manufacturing methodfurther includes the following steps. Before the molding compound isformed on the redistribution layer, a dielectric layer is formed on theredistribution layer. The dielectric layer covers the LEDs. The activesurface of each of the LEDs is aligned to a surface of the dielectriclayer. The dielectric layer includes a plurality of openings to expose aportion of the redistribution layer. A plurality of circuits are formedin the openings, and extend to the surface of the dielectric layer toconnect the active surface of each of the LEDs.

According to an embodiment of the disclosure, the manufacturing methodfurther includes the following step. After the molding compound isformed on the redistribution layer and before the carrier is removed, anoptical base material is provided on a top surface of the moldingcompound.

According to an embodiment of the disclosure, the manufacturing methodfurther includes the following step. After the carrier is removed toexpose the bottom surface of the redistribution layer, a surfacetreatment layer is formed on the bottom surface of the redistributionlayer.

According to an embodiment of the disclosure, an LED package structureincludes a redistribution layer, a plurality of active devices, aplurality of LEDs and a molding compound. The active devices aredisposed on the redistribution layer, and are electrically connected tothe redistribution layer. The LEDs are disposed on the redistributionlayer, and are electrically connected to the redistribution layer. Theactive devices are adapted to respectively drive the LEDs. The moldingcompound is disposed on the redistribution layer, and encapsulates theLEDs.

According to an embodiment of the disclosure, the redistribution layerincludes a top surface and a bottom surface opposite to each other, andincludes a first circuit structure adjacent to the top surface and asecond circuit structure adjacent to the bottom surface.

According to an embodiment of the disclosure, the active devices and theLEDs are located on the first circuit structure.

According to an embodiment of the disclosure, each of the LEDs includesan active surface and a back surface opposite to each other, and theactive surface is located between the back surface and theredistribution layer.

According to an embodiment of the disclosure, the LED package structurefurther includes a dielectric layer and a surface treatment layer. Thedielectric layer is disposed on the redistribution layer. The dielectriclayer covers the active devices, and includes a plurality of openings toexpose a portion of the redistribution layer. The surface treatmentlayer is disposed in the openings, and directly contacts theredistribution layer.

According to an embodiment of the disclosure, each of the LEDs includesan active surface and a back surface opposite to each other, and theback surface is located between the active surface and theredistribution layer.

According to an embodiment of the disclosure, the LED package structurefurther includes a dielectric layer and a plurality of circuits. Thedielectric layer is disposed on the redistribution layer, and covers theactive devices and the LEDs. The active surface of each of the LEDs isaligned to a surface of the dielectric layer. The dielectric layerincludes a plurality of openings to expose a portion of theredistribution layer. The circuits are disposed in the openings, andextend to the surface of the dielectric layer to connect the activesurface of each of the LEDs.

According to an embodiment of the disclosure, the LEDs are located onthe first circuit structure, and the active devices and the secondcircuit structure are located on a same plane.

According to an embodiment of the disclosure, each of the LEDs includesan active surface and a back surface opposite to each other, and theactive surface is located between the back surface and theredistribution layer.

According to an embodiment of the disclosure, the LED package structurefurther includes a dielectric layer and a surface treatment layer. Thedielectric layer is disposed on the redistribution layer, wherein thedielectric layer includes a plurality of openings to expose a portion ofthe redistribution layer. The surface treatment layer is disposed in theopenings, and directly contacts the redistribution layer.

According to an embodiment of the disclosure, each of the LEDs includesan active surface and a back surface opposite to each other, and theback surface is located between the active surface and theredistribution layer.

According to an embodiment of the disclosure, the LED package structurefurther includes a dielectric layer and a plurality of circuits. Thedielectric layer is disposed on the redistribution layer, and covers theLEDs. The active surface of each of the LEDs is aligned to a surface ofthe dielectric layer. The dielectric layer includes a plurality ofopenings to expose a portion of the redistribution layer. The circuitsare disposed in the openings, and extend to the surface of thedielectric layer to connect the active surface of each of the LEDs.

According to an embodiment of the disclosure, the LED package structurefurther includes an optical base material provided on a top surface ofthe molding compound.

Based on the above, according to the LED package structure and themanufacturing method of the LED package structure according to theembodiments of the disclosure, the LEDs are transferred onto theredistribution layer electrically connected to the active devices, andthe active devices are adapted to drive the LEDs. As such, the issuethat electronic devices cannot be soldered on the back surface of aglass substrate is addressed. In addition, since the active devices areemployed to drive the LEDs in the embodiments of the disclosure, the LEDpackage structure and the manufacturing method of the LED packagestructure according to the embodiments of the disclosure render a lowercost in comparison with the conventional art, in which the passivedevices are used for driving.

In order to make the aforementioned features and advantages of thedisclosure comprehensible, embodiments accompanied with figures aredescribed in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the disclosure, and are incorporated in and constitutea part of this specification. The drawings illustrate embodiments of thedisclosure and, together with the description, serve to explain theprinciples of the disclosure.

FIGS. 1A to 1I are schematic cross-sectional views illustrating amanufacturing method of a light emitting diode (LED) package structureaccording to an embodiment of the disclosure.

FIG. 2 is a schematic cross-sectional view illustrating the LED packagestructure of FIG. 1I bonded to a circuit board.

FIGS. 3A to 3G are schematic cross-sectional views illustrating somesteps of a manufacturing method of an LED package structure according toan alternative embodiment of the disclosure.

FIG. 4 is a schematic cross-sectional view illustrating the LED packagestructure of FIG. 3G bonded to a circuit board.

FIGS. 5A to 5E are schematic cross-sectional views illustrating amanufacturing method of an LED package structure and the applicationthereof according to another embodiment of the disclosure.

FIGS. 6A to 6E are schematic cross-sectional views illustrating amanufacturing method of an LED package structure and the applicationthereof according to another embodiment of the disclosure.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the exemplary embodiments of thedisclosure, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers are used in thedrawings and the description to refer to the same or like parts.

FIGS. 1A to 1I are schematic cross-sectional views illustrating amanufacturing method of a light emitting diode (LED) package structureaccording to an embodiment of the disclosure. Regarding themanufacturing method of the LED package structure according to theembodiment, as shown in FIG. 1A, a carrier 10 is provided. Here, thecarrier 10 is a glass substrate.

Next, referring to FIG. 1B, a release film 12 is formed on the carrier10. The release film 12 may be formed by spin coating, for example.However, the disclosure is not limited thereto.

Next, referring to FIG. 1C, a redistribution layer 110 a is formed onthe carrier 10. The redistribution layer 110 a is located on the releasefilm 12 and includes a top surface 111 a and a bottom surface 113 aopposite to each other as well as a first circuit structure 112 aadjacent to the top surface 111 a and a second circuit structure 114 aadjacent to the bottom surface 113 a. The bottom surface 113 a isattached to the release film 12 on the carrier 10, and the top surface111 a is located on a side relatively away from the carrier 10. Here,the first circuit structure 112 a includes a patterned line layer or aplurality of pads, and the second line structure 114 a includes aplurality of conductive vias or a plurality of circuits.

Next, referring to FIG. 1D, a plurality of active devices 120 a areformed on the carrier 10. More specifically, the active devices 120 amay be thin film transistors (TFTs), for example. However, thedisclosure is not limited thereto. The active devices 120 a are formedon the side of the redistribution layer 110 a relatively away from thecarrier 10, and are located on the first circuit structure 112 a andelectrically connected to the first circuit structure 112 a. That is, inthe embodiment, the active devices 120 a are manufactured on theredistribution layer 110 a.

Referring to FIG. 1E, a dielectric layer 115 is formed on theredistribution layer 110 a. The dielectric layer 115 covers the activedevices 120 a, and includes a plurality of openings 115 a to expose aportion of the redistribution layer 110 a. Here, the openings 115 aexpose a portion of the first circuit structure 112 a of theredistribution layer 110 a. Next, a surface treatment layer 125 isformed in the openings 115 a of the dielectric layer 115 and directlycontacts the redistribution layer 110 a. The surface treatment layer 125is formed on the first circuit structure 112 a exposed by the openings115 a of the dielectric layer 115 to protect the first circuit structure112 a from oxidation. Here, the surface treatment layer 125 may be anickel layer, a gold layer, a silver layer, or a nickel-palladium-goldlayer, but is not limited thereto.

Next, referring to FIG. 1F, a plurality of LEDs 130 a are transferredonto the redistribution layer 110 a. The LEDs 130 a and the activedevices 120 a are located on the same side of the redistribution layer110 a. More specifically, each of the LEDs 130 a includes a back surface132 a and an active surface 134 a opposite to each other, and the activesurface 134 a is located between the back surface 132 a and theredistribution layer 110 a. That is to say, the LEDs 130 a are arrangedon the redistribution layer 110 a with the active surface 134 a facingdown. The LEDs 130 a are located on the first circuit structure 112 a onwhich the surface treatment layer 125 is arranged. The surface treatmentlayer 125 is located between the LEDs 130 a and the first circuitstructure 112 a. The LEDs 130 a and the active devices 120 a arerespectively electrically connected to the redistribution layer 110 a.The active devices 120 a are adapted to respectively drive the LEDs 130a. In particular, the orthographic projections of the LEDs 130 a on thecarrier 10 do not overlap with the orthographic projections of theactive devices 120 a on the carrier 10. Here, three LEDs 130 a areschematically drawn in FIG. 1F, and, for example, are respectively a redLED, a blue LED and a green LED. However, the disclosure is not limitedthereto. According to an exemplary embodiment, the LEDs 130 are microLEDs.

Next, referring to FIG. 1G, a molding compound 140 is formed on theredistribution layer 110 a to encapsulate the LEDs 130 a. Here, themolding compound 140 covers the back surfaces 132 a of the LEDs 130 a,and keeps a distance G from the back surfaces 132 a for planarization.According to an exemplary embodiment, the molding compound 140 includessilicone and serves to fix the LEDs 130 a.

According to FIG. 1G, an optical base material 150 is provided on a topsurface 142 of the molding compound 140. The optical base material 150is capable of rendering favorable optical performance of the lightemitted by the LEDs 130 a. For example, the optical base material 150 isan optical plate or an optical film. For example, the optical plate maybe a light guide plate, and the optical film is a diffuser, a prism or abrightness enhancement film, or an anti-reflection (anti-glare) film.However, the disclosure is not limited thereto.

Finally, referring to both FIG. 1H and FIG. 1I, the carrier 10 isremoved to expose the bottom surface 113 a of the redistribution layer110 a. When the carrier 10 is removed, the release film 12 is peeled offto separate the redistribution 110 a and the carrier 10. A surfacetreatment may be optionally performed on the second circuit structure114 a of the redistribution layer 110 a to form a surface treatmentlayer 127 on the bottom surface 113 a of the redistribution layer 110 aand thereby protect the second circuit structure 114 a. By this time,the manufacturing of the LED package structure 100 a has been completed.

Regarding the structure, referring to FIG. 1I, the LED package structure100 a includes the redistribution layer 110 a, the active devices 120 a,the LEDs 130 a and the molding compound 140. The redistribution layer110 a includes the top surface 111 a and the bottom surface 113 aopposite to each other, and includes the first circuit structure 112 aadjacent to the top surface 111 a and the second circuit structure 114 aadjacent to the bottom surface 113 a. The active devices 120 a and theLEDs 130 a are both disposed on the redistribution layer 110 a, and areboth electrically connected to the redistribution layer 110 a. Theactive devices 120 a are adapted to respectively drive the LEDs 130 a.More specifically, the active devices 120 a and the LEDs 130 a arelocated on the first circuit structure 112 a. For planarization, themolding compound 140 is disposed on the redistribution layer 110 a toencapsulate the LEDs 130 a.

In addition, the LED package structure 100 a of the embodiment furtherincludes the surface treatment layers 125 and 127. The surface treatmentlayer 125 is arranged between the LEDs 130 a and the first circuitstructure 112 a to protect the first circuit structure 112 a, and thesurface treatment layer 127 is arranged on the bottom surface 113 a ofthe redistribution layer 110 a to protect the second circuit structure114 a. According to the embodiment, the LED package structure 100 afurther includes the optical base material 150 arranged on the topsurface 142 of the molding compound 140. For example, the optical basematerial 150 is an optical plate or an optical film, and is utilized forenhancing the optical performance of the LEDs 130 a.

In short, according to the embodiment, after the active devices 120 aare first manufactured on the redistribution layer 110 a, the LEDs 130 aare transferred onto the redistribution layer 110 a. Particularly, theLEDs 130 a are arranged on the first circuit structure 112 a of theredistribution layer 110 a with the active surfaces 132 a facing down,and the active devices 120 a are adapted to drive the LEDs 130 a. Thatis, the LED package structure 100 a of the embodiment is implemented tobe an active LED package structure. As such, the issue that electronicdevices cannot be soldered on the back surface of a glass substrate isaddressed. In addition, according to the embodiment, the active devices120 a are employed to drive the LEDs 130 a, so the LED package structure110 a and the manufacturing method of the LED package structure 110 arender a lower cost in comparison with the conventional art, in whichthe passive devices are used for driving.

As to the application, referring to FIG. 2, the LED package structure100 a of the embodiment may be bonded to an external circuit 20, so thatthe second circuit structure 114 a of the redistribution layer 110 a iselectrically connected with pads 22 of the external circuit 20 areelectrically connected. Here, the external circuit 20 is a printedcircuit board (PCB), for example, but the disclosure is not limitedthereto. Also, FIG. 2 merely illustrates one LED package structure 100 abonded to the external circuit 20 for a schematic purpose. If multipleLED package structures 100 a are bonded to the external circuit 20 bysplicing, a large-scale display can be formed.

In the aforementioned manufacturing method of the LED package structure110, the redistribution layer 110 a is formed on the carrier 10 beforethe active devices 120 a are formed on the carrier 10. However, thedisclosure is not limited thereto. In other embodiments, the activedevices 120 a may also be formed on the carrier 10 before theredistribution layer 110 a is formed on the carrier 10.

The following embodiments use the reference numerals and a part of thecontents of the above embodiments, and the same reference numerals areused to denote the same or similar elements, while the description ofthe same technical contents is omitted. For the description of theomitted part, reference may be made to the above embodiments, anddetails will not be repeated in the following embodiments.

FIGS. 3A to 3G are schematic cross-sectional views illustrating somesteps of a manufacturing method of an LED package structure according toan alternative embodiment of the disclosure. The manufacturing method ofthe LED package structure according to the embodiment is similar to themanufacturing method of the LED package structure described above, butdiffers in that, after the release film 12 is formed on the carrier 10as shown in FIG. 1B, active devices 120 b are formed on the carrier 10,as shown in FIG. 3A. Specifically, the active devices 120 b are locatedon the release film 12.

Next, referring to FIG. 3B, a redistribution layer 110 b is formed onthe carrier 10. The redistribution layer 110 b is located on the releasefilm 12. Here, the active devices 120 b and a second circuit structure110 b of the redistribution layer 110 b are located on the same plane.

Then, referring to FIG. 3B, a dielectric layer 117 is formed on theredistribution layer 110 b. The dielectric layer 117 includes aplurality of openings 117 a exposing a first circuit structure 112 b.

Next, referring to FIG. 3C, the surface treatment layer 125 is formed inthe openings 117 a of the dielectric layer 117, and directly contactsthe first circuit structure 112 b of the redistribution layer 110 b toprotect the first line structure 112 b from oxidation.

Next, referring to FIG. 3D, the LEDs 130 a are transferred onto theredistribution layer 110 b. Specifically, the LEDs 130 a are arranged onthe first circuit structure 112 b of the redistribution layer 110 b withthe active surfaces 134 a facing down, and the surface treatment layer125 is located between the LEDs 130 a and the first circuit structure112 b.

Next, referring to FIG. 3E, the molding compound 140 is formed on theredistribution layer 110 b to encapsulate the LEDs 130 a. Next, theoptical base material 150 is provided on the top surface 142 of themolding compound 140. The optical base material 150, for example, is anoptical plate or an optical film.

Finally, referring to FIG. 3F and FIG. 3G, the carrier 10 is removed,and the release film 12 is peeled off to expose a bottom surface 113 bof the redistribution layer 110 b and surfaces 122 b of the activedevices 120 b. A surface treatment may be optionally performed on thesecond circuit structure 114 b of the redistribution layer 110 b to formthe surface treatment layer 127 on the bottom surface 113 b of theredistribution layer 110 b and thereby protect the second circuitstructure 114 b. By this time, the manufacturing of the LED packagestructure 100 b has been completed.

Regarding the structure, referring to FIG. 3G, the LED package structure100 b includes the redistribution layer 110 b, the active devices 120 b,the LEDs 130 a and the molding compound 140. The redistribution layer110 b includes a top surface 111 b and the bottom surface 113 b oppositeto each other, and includes the first circuit structure 112 b adjacentto the top surface 111 b and the second line structure 114 b adjacent tothe bottom surface 113 b. The active devices 120 b and the secondcircuit structure 114 b are located on the same plane, and the LEDs 130a are located on the first circuit structure 112 b. The active devices120 b and the LEDs 130 a are respectively electrically connected to theredistribution layer 110 b. The active devices 120 b are adapted torespectively drive the LEDs 130 a. The molding compound 140 is disposedon the redistribution layer 110 b to encapsulate the LEDs 130 a forplanarization.

In addition, the LED package structure 100 b of the embodiment furtherincludes the surface treatment layers 125 and 127. The surface treatmentlayer 125 is arranged between the LEDs 130 a and the first circuitstructure 112 b to protect the first circuit structure 112 b, and thesurface treatment layer 127 is arranged on the bottom surface 113 b ofthe redistribution layer 110 b to protect the second circuit structure114 b. The LED package structure 100 b of the embodiment furtherincludes the optical base material 150 arranged on the top surface 142of the molding compound 140. For example, the optical base material 150is an optical plate or an optical film, and is utilized for enhancingthe optical performance of the LEDs 130 a.

In short, according to the embodiment, after the active devices 120 bare first manufactured, the redistribution layer 110 b electricallyconnected to the active devices 120 b is manufactured, and the LEDs 130a are transferred onto the redistribution layer 110 b. Also, the activedevices 120 b are adapted to drive the LEDs 130 a. That is, the LEDpackage structure 100 b of the embodiment is implemented to be an activeLED package structure. By doing so, the issue that electronic devicescannot be soldered on the back surface of a glass substrate isaddressed. In addition, according to the embodiment, the active devices120 b are employed to drive the LEDs 130 a, so the LED package structure110 b and the manufacturing method of the LED package structure 110 brender a lower cost in comparison with the prior art, in which thepassive devices are used for driving.

As to the application, referring to FIG. 4, the LED package structure100 b of the embodiment may be bonded to the external circuit 20, sothat the second circuit structure 114 b of the redistribution layer 110b is electrically connected with the pads 22 of the external circuit 20.FIG. 4 merely illustrates one LED package structure 100 b bonded to theexternal circuit 20 for a schematic purpose. If multiple LED packagestructures 100 b are bonded to the external circuit 20 by splicing, alarge-scale display can be formed.

FIGS. 5A to 5E are schematic cross-sectional views illustrating amanufacturing method of an LED package structure and the applicationthereof according to another embodiment of the disclosure. Themanufacturing method of the LED package structure of the embodiment issimilar to the manufacturing method of the LED package structure 100 a,but differs in a step that after the step of FIG. 1D, i.e., after aplurality of active devices 120 c are formed on the carrier 10, aplurality of LEDs 130 b are transferred onto a redistribution layer 110c, as shown in FIG. 5A. The LEDs 130 b and the active devices 120 c arelocated on the same side of the redistribution layer 110 c. Morespecifically, each of the LEDs 130 b includes a back surface 132 b andan active surface 134 b opposite to each other, and the back surface 132b is located between the active surface 134 b and the redistributionlayer 110 c. Note that, the LEDs 130 b are arranged with the activesurfaces 134 b facing up, and are adhered to the redistribution layer110 c through an adhesion layer 160.

Referring to FIG. 5B, a dielectric layer 118 is formed on theredistribution layer 110 c. The dielectric layer 118 covers the activedevices 120 c and the LEDs 130 b. The active surface 134 b of each ofthe LEDs 130 b is aligned with a surface 118 b of the dielectric layer118, and the dielectric layer 118 includes a plurality of openings 118 ato expose a portion of a first circuit structure 112 c of theredistribution layer 110 c.

Referring to FIG. 5C, a plurality of circuits 170 are formed in theopenings 118 a, and extend to the surface 118 b of the dielectric layer118 to connect the active surfaces 134 b of the respective LEDs 130 b.Next, the molding compound 140 is formed on the redistribution layer 110c to encapsulate the LEDs 130 c and the circuits 170. The moldingcompound 140 covers the active surfaces 134 b of the LEDs 130 b, andkeeps a distance G′ from the active surfaces 134 b for planarization.

Referring to FIG. 5C, the optical base material 150 is provided on thetop surface 142 of the molding compound 140. The optical base material150 may serve for the LEDs 130 b to render favorable opticalperformance. The optical base material 150 is, for example, is anoptical plate or an optical film.

Referring to FIG. 5D and FIG. 5E, the carrier 10 is removed to expose abottom surface 113 c of the redistribution layer 110 c. When the carrier10 is removed, the release film 12 is peeled off to separate theredistribution layer 110 c and the carrier 10. A surface treatment maybe optionally performed on a second circuit structure 114 c of theredistribution layer 110 c to form the surface treatment layer 127 onthe bottom surface 113 c of the redistribution layer 110 c and therebyprotect the second line structure 114 c. By this time, the manufacturingof the LED package structure 100 c has been completed.

As to the application, referring to FIG. 5E, the LED package structure100 c of the embodiment may be bonded to the external circuit 20, sothat the second circuit structure 114 c of the redistribution layer 110c is electrically connected with the pads 22 of the external circuit 20.Here, the external circuit 20 is the PCB, for example, but thedisclosure is not limited thereto. FIG. 5E merely illustrates one LEDpackage structure 100 c bonded to the external circuit 20 for aschematic purpose. If multiple LED package structures 100 c are bondedto the external circuit 20 by splicing, a large-scale display can beformed.

FIGS. 6A to 6E are schematic cross-sectional views illustrating amanufacturing method of an LED package structure and the applicationthereof according to another embodiment of the disclosure. Themanufacturing method of the LED package structure of the embodiment issimilar to the manufacturing method of the LED package structure 100 bdescribed in the above, but differs in that after the step of FIG. 3B,i.e. after a redistribution layer 110 d is formed on the carrier 10, theLEDs 130 b are transferred onto the redistribution layer 110 d, as shownin FIG. 6A. The LEDs 130 b are located on the redistribution layer 110 dwith the active surfaces 134 facing up.

Next, referring to FIG. 6B, a dielectric layer 119 is formed on theredistribution layer 110 d. The dielectric layer 119 includes aplurality of openings 119 a which expose a first circuit structure 112d. Next, the circuits 170 are formed in the openings 119 a, and extendto a surface 119 b of the dielectric layer 119 to connect the activesurfaces 134 b of the respective LEDs 130 b.

Next, referring to FIG. 6C, the molding compound 140 is formed on theredistribution layer 110 d to encapsulate the LEDs 130 d and thecircuits 170. Here, the molding compound 140 covers the active surfaces134 b of the LEDs 130 b.

According to FIG. 6C, the optical base material 150 is provided on thetop surface 142 of the molding compound 140. Here, the optical basematerial 150 allows the light emitted by the LEDs 130 b to renderfavorable optical performance. The optical base material 150 may be anoptical plate or an optical film, for example.

Finally, referring to FIG. 6D and FIG. 6E, the carrier 10 is removed,and the release film 12 is peeled off to expose a bottom surface 113 dof the redistribution layer 110 d and surfaces 122 d of the activedevices 120 d. A surface treatment may be optionally performed on asecond circuit structure 114 d of the redistribution layer 110 d to formthe surface treatment layer 127 on the bottom surface 113 d of theredistribution layer 110 d and thereby protect the second circuitstructure 114 d. By this time, the manufacturing of the LED packagestructure 100 d has been completed.

As to the application, referring to FIG. 6E, the LED package structure100 d of the embodiment is bonded to the external circuit 20, so thatthe second circuit structure 114 d of the redistribution layer 110 d iselectrically connected with the pads 22 of the external circuit 20. FIG.6E merely illustrates one LED package structure 100 d bonded to theexternal circuit 20 for a schematic purpose. If multiple LED packagestructures 100 d are bonded to the external circuit 20 by splicing, alarge-scale display can be formed.

Based on the above, according to the LED package structure and themanufacturing method of the LED package structure according to theembodiments of the disclosure, the LEDs are transferred onto theredistribution layer electrically connected to the active devices, andthe active devices are adapted to drive the LEDs. As such, the issuethat electronic devices cannot be soldered on the back surface of aglass substrate is addressed. In addition, since the active devices areemployed to drive the LEDs in the embodiments of the disclosure, the LEDpackage structure and the manufacturing method of the LED packagestructure according to the embodiments of the disclosure render a lowercost in comparison with the conventional art, in which the passivedevices are used for driving.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of thedisclosure without departing from the scope or spirit of the disclosure.In view of the foregoing, it is intended that the disclosure covermodifications and variations of the disclosure provided they fall withinthe scope of the following claims and their equivalents.

What is claimed is:
 1. A light emitting diode (LED) package structurecomprising: a redistribution layer, wherein the redistribution layercomprises a top surface and a bottom surface opposite to each other, andcomprises a first circuit structure adjacent to the top surface and asecond circuit structure adjacent to the bottom surface; a plurality ofactive devices, disposed on the redistribution layer and electricallyconnected to the redistribution layer; a plurality of light emittingdiodes, disposed on the redistribution layer and electrically connectedto the redistribution layer, wherein the plurality of active devices areadapted to respectively drive the plurality of light emitting diodes;and a molding compound, disposed on the redistribution layer andencapsulating the plurality of light emitting diodes, wherein theplurality of active devices and the plurality of light emitting diodesare located directly on the first circuit structure.
 2. The lightemitting diode package structure of claim 1, wherein each of theplurality of light emitting diodes comprises an active surface and aback surface opposite to each other, and the active surface is locatedbetween the back surface and the redistribution layer.
 3. The lightemitting diode package structure of claim 1 further comprising: adielectric layer, disposed on the redistribution layer, wherein thedielectric layer covers the plurality of active devices, and comprises aplurality of openings to expose a portion of the redistribution layer;and a surface treatment layer, disposed in the plurality of openings anddirectly contacting the redistribution layer.
 4. The light emittingdiode package structure of claim 1, wherein each of the plurality oflight emitting diodes comprises an active surface and a back surfaceopposite to each other, and the back surface is located between theactive surface and the redistribution layer.
 5. The light emitting diodepackage structure of claim 4 further comprising: a dielectric layer,disposed on the redistribution layer, wherein the dielectric layercovers the plurality of active devices and the plurality of lightemitting diodes, the active surface of each of the plurality of lightemitting diodes is aligned to a surface of the dielectric layer, and thedielectric layer comprises a plurality of openings to expose a portionof the redistribution layer; and a plurality of circuit, disposed in theplurality of openings and extending to the surface of the dielectriclayer to connect the active surface of each of the plurality of lightemitting diodes.
 6. The light emitting diode package structure of claim1, wherein the plurality of light emitting diodes are located on thefirst circuit structure, and the plurality of active devices and thesecond circuit structure are located on a same plane.
 7. The lightemitting diode package structure of claim 6, wherein each of theplurality of light emitting diodes comprises an active surface and aback surface opposite to each other, and the active surface is locatedbetween the back surface and the redistribution layer.
 8. The lightemitting diode package structure of claim 7 further comprising: adielectric layer, disposed on the redistribution layer, wherein thedielectric layer comprises a plurality of openings to expose a portionof the redistribution layer; and a surface treatment layer, disposed inthe plurality of openings and directly contacting the redistributionlayer.
 9. The light emitting diode package structure of claim 6, whereineach of the plurality of light emitting diodes comprises an activesurface and a back surface opposite to each other, and the back surfaceis located between the active surface and the redistribution layer. 10.The light emitting diode package structure of claim 9 furthercomprising: a dielectric layer, disposed on the redistribution layer,wherein the dielectric layer covers the plurality of light emittingdiodes, the active surface of each of the plurality of light emittingdiodes is aligned to a surface of the dielectric layer, and thedielectric layer comprises a plurality of openings to expose a portionof the redistribution layer; and a plurality of circuit, disposed in theplurality of openings and extending to the surface of the dielectriclayer to connect the active surface of each of the plurality of lightemitting diodes.
 11. The light emitting diode package structure of claim1 further comprising: an optical base material, disposed on a topsurface of the molding compound.